Evolutionists generally feel secure even in the face of compelling creationist arguments today because of their utter confidence in the geological time scale.
Even if they cannot provide a naturalistic mechanism, they appeal to the "fact of evolution," by which they mean an interpretation of earth history with a succession of different types of plants and animals in a drama spanning hundreds of millions of years.
Also called absolute dating, scientists use the decay of radioactive elements within the fossils or the rocks around the fossils to determine the age of the organism that was preserved.
However, radioisotope dating may not work so well in the future.
Anything that dies after the 1940s, when Nuclear bombs, nuclear reactors and open-air nuclear tests started changing things, will be harder to date precisely.
Desmond Clark (1979) wrote that were it not for radiocarbon dating, "we would still be foundering in a sea of imprecisions sometime bred of inspired guesswork but more often of imaginative speculation" (Clark, 1979:7).
Writing of the European Upper Palaeolithic, Movius (1960) concluded that "time alone is the lens that can throw it into focus".